Human growth hormone, or HGH, is naturally present in the body. As we age the amount of HGH decreases. Can replacing this hormone reverse the signs of aging? Some medical practitioners believe it can, and prescribe it off-label for their patients to increase muscle mass, reduce body fat, increase bone density, and build endurance. Such benefits can indeed improve a patient’s life; it is not surprising that people increasingly seek out medical providers who prescribe HGH to improve patients’ quality of life.